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I do like having the option for 80%. Once in a while I really need to go past it.
As batteries age they don't just act like a gas tank with less gas. They act like batteries in a flashlight. The voltage and ability to provide current goes down. The affect of range could be more than the calculated reduction in kWh or amp hours.
 
I do like having the option for 80%. Once in a while I really need to go past it.
As batteries age they don't just act like a gas tank with less gas. They act like batteries in a flashlight. The voltage and ability to provide current goes down. The affect of range could be more than the calculated reduction in kWh or amp hours.
Yeah I put more stock in the ~46 kWh used going from 100%-16%, which still works out to about 10% loss. Actually, since I don’t use torque pro, I put ALL my stock in the kWh used vs. SoC calc.

Given the state of EVs when our 2017 was made, I’ll take 10% loss over ~150k miles any day of the week.
 
I'll accept a 10% loss of battery life over 150k miles, seeing as how I've only owned 1 car that made it past 150k.
Don't forget to account for the unknown buffer that GM built in to the batteries. We don't get to see that extra amount and once it's used up then the battery management starts eating up the stuff we can count.
 
Don't forget to account for the unknown buffer that GM built in to the batteries. We don't get to see that extra amount and once it's used up then the battery management starts eating up the stuff we can count.
What? There is no "stuff we don't get to see." The maximum and minimum voltage is set, and is not going to change as the capacity goes down. If GM set our max voltage to 4.00 volts per cell, and the minimum to 3.50 volts, they could, in theory, expand that range when the battery has lost some percentage of capacity. But that would only accelerate the death spiral.


Our charging to 80% slows degradation, and when the capacity drops to 80% of original, we could go to charging to 100% to maintain range, but that would speed the degradation. There is no free lunch.
 
What? There is no "stuff we don't get to see." The maximum and minimum voltage is set, and is not going to change as the capacity goes down. If GM set our max voltage to 4.00 volts per cell, and the minimum to 3.50 volts, they could, in theory, expand that range when the battery has lost some percentage of capacity. But that would only accelerate the death spiral.


Our charging to 80% slows degradation, and when the capacity drops to 80% of original, we could go to charging to 100% to maintain range, but that would speed the degradation. There is no free lunch.
I stand corrected
 
Very good information given in this thread.... I love this forum! I recently just got my letter for battery replacement and as soon as it arrives at my dealer I will be getting a New/replacement pack/battery modules. I currently have 42,000 after two years of commuting. I still get about 230 at 80% top charge (limited by software). My recumbent reports show I am at the top of the curve for mileage at a score of 106. I checked my Dealer and the Tech there has done about 80 battery replacements so far and I feel confident He is going to get it right... fingers crossed.
I think knowing what I now know, I am going to keep some better records and data on this new battery!
Go Bolt Nation!
 
Very good information given in this thread.... I love this forum! I recently just got my letter for battery replacement and as soon as it arrives at my dealer I will be getting a New/replacement pack/battery modules. I currently have 42,000 after two years of commuting. I still get about 230 at 80% top charge (limited by software). My recumbent reports show I am at the top of the curve for mileage at a score of 106. I checked my Dealer and the Tech there has done about 80 battery replacements so far and I feel confident He is going to get it right... fingers crossed.
I think knowing what I now know, I am going to keep some better records and data on this new battery!
Go Bolt Nation!
How long can you sit on it if you want to wait? If you don’t need it yet, wait it out?
 
How long can you sit on it if you want to wait? If you don’t need it yet, wait it out?
I can't answer that one.... maybe someone (Guru) can help you on that
If @Electric Personality is asking in general whether GM will allow a Bolt owner to wait to replace the battery, the answer is generally yes. The recall instructions state, "Dealers are to service all vehicles subject to this recall at no charge to customers, regardless of mileage, age of vehicle, or ownership, from this time forward." So in theory, you could wait until your battery warranty expired, and then go get a replacement battery under the recall. In practice, it's possible that GM will stop producing these batteries, and you may end up with refurbished battery modules or a different remedy.

If @Electric Personality is asking whether @brichard is in any rush to replace the battery, and might choose to wait a little longer (to extend the benefit of getting a new battery with a new warranty), well, @brichard can answer that one.
 
At the request of @p7wang, and for the sake of sharing good data (I hope 😅), the following is what I believe to be accurate statements and data points regarding my 2019 Bolt, and it's original ~200 amp hour battery, after 4 years and 165,000 miles of use. As of a few days ago, my Torque Pro (TP) estimated battery capacity is just above 54kwh/169 amp hours. I did a drive with most all highway driving, from full charge, down to a displayed 16% SOC, photographing the car displayed and TP data, to try to corroborate/check for discrepancies, and see how linear the battery energy is, with the displayed SOC. I am very content with performance and the results.




Due yourself a BIG favor and DO NOT REPLACE THAT BATTERY. Tell us how long it takes you to charge to 80% from 20 %. New battery it will take 2- 2.5 hours.
 
Discussion starter · #32 ·
Due yourself a BIG favor and DO NOT REPLACE THAT BATTERY. Tell us how long it takes you to charge to 80% from 20 %. New battery it will take 2- 2.5 hours.
Can you please provide a source for this claim? It takes a Bolt with the old software and battery, roughly about an hour to go from 20%-80%.
 
Discussion starter · #33 · (Edited)
Due yourself a BIG favor and DO NOT REPLACE THAT BATTERY. Tell us how long it takes you to charge to 80% from 20 %. New battery it will take 2- 2.5 hours.
According to Tom Moloughney's data (which is way more often than not, spot on), it is in direct contrast of what you're claiming. However, if you take a cold "soaked" battery to a DC fast charging station (maybe colder than 40°F), and you would likely experience the circumstance you mentioned. Feel free to PM details if you prefer.

The below image is from the "State of Charge" channel on YouTube.

 
It's not the battery, it is the software. They put in limits. Also if you have noticed top speed is 92mph. I do not drive that fast, just wanted to see top speed.
I don't think it is only SW that limits the Bolt DC charging speed. I think it is wiring, and to some extent, limited thermal cooling.

Theoretically, the chemistry in Bolt battery cells should tolerate ~1C charging rate, or 65 kW average speed over an hour. Yet, it takes around 2 hours to charge a Bolt from 0-100% on DCFC, so the effective rate of charge is closer to .5C or half what the cells could accept.

Bolt was likely designed during a period when 50kW DCFC was the standard, and 150kW or greater were only imagined. So, they likely engineered the wiring and cooling to match "state of the art". Since GM essentially abandoned Bolt R&D once the car hit the market, favoring putting their efforts into Ultium, they never went back and addressed this design limitation.
 
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I don't think it is only SW that limits the Bolt DC charging speed. I think it is wiring, and to some extent, limited thermal cooling.

Theoretically, the chemistry in Bolt battery cells should tolerate ~1C charging rate, or 65 kW average speed over an hour. Yet, it takes around 2 hours to charge a Bolt from 0-100% on DCFC, so the effective rate of charge is closer to .5C or half what the cells could accept.

Bolt was likely designed during a period when 50kW DCFC was the standard, and 150kW or greater were only imagined. So, they likely engineered the wiring and cooling to match "state of the art". Since GM essentially abandoned Bolt R&D once the car hit the market, favoring putting their efforts into Ultium, they never went back and addressed this design limitation.
So, you are saying that they changed the wiring in my Bolt when they changed the battery. Before the battery swap I could charge at any DCFC to 80% in 30 min. It now takes 2- 2.5 hrs, and I can no longer use the stations that I was before the swap. Maybe you missed this part.
 
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